Fire-escape.



i mk

C. V. LINDHOLM.

FIRE ESCAPE.

PPLIoATIoN FILED 1211.21, 1911;

Irl/6 Patented Sept. 12, 1911.

CHARLES V. EINDE-IULM, OF CHICAGO, LLINOIS,

FIRE-ESCAPE.

Specification of Letters Patent.

Patented Sept. 12, 1911.

Application lecl April 21, 1911. Serial No. 622,572.

To all whom it may concern:

Be it known that l, CHARLES V. LIND- HoLM, a citizen of the United States, and a resident of the cit-y of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Fire-Escapes, of which the following is a specification.

My invention relates to improvements in fire escapes and more specifically to the lower pivoted stair-section of a conventional fire escape. At the present time this stairsection of the fire escape is provided at its pivoted end with a counter weight which is secured to the outer stringer thereof. It has been found that unless provision is made, the corner at the free end of the stairsection opposite to that at which the counter weight is secured sags.

The object of the present invention is to so construct this stair-section of the fire escape that the corner thereof opposite that to which the counter weight is secured will be prevented from sagging.

A further object is the provision of a fire escape construction as mentioned, which will be durable and economical and eliicient in operation.

Other objects will appear hereinafter.

With these objects in view my invention consists in a lire escape characterized as above mentioned and vin certain details of construction and arrangement of parts all as will be hereinafter more fully described and particularly pointed out in the appen ded claims.

My invention will be more readily understood by reference to the accompanying drawing forming a part of this specification, and in which,

Figure 1 is an inner side elevation .of a swinging lire escape stair-section embody- .ing my invention, the same being shown in incomplete condition, Fig. 2 is a similar view thereof completed, Fig. 3 is a slightly enlarged detail section taken on line of Fig. 2, Fig. 4: is a detail perspective view of one of the step ytread-bars, and Fig. 5 is a detail of one of the end members included in each of the steps.

. The preferred form of my construction as illustrated in the drawing comprises outer and inner stringers, the former being formed of two separated parallel longitudinal bars 1 and 2 and the latter of correspondingly positioned bars 3 and l. Extending between and connecting said stringers at intervals are the steps which are arranged in the usual manner so that when the free end of the stair-section is lowered into contact with the ground, said steps will assume a horizontal position. Each of the steps comprises end pieces 5 which are rigidly secured to the Stringer bars at 6. Extending between the end pieces 5 are tread-forming bars 7, the respective ends of said bars 7 being flattened for snug engage ment with correspondingly formed slots 9 provided in said end pieces, a rigid step construction being thus provided.

The stair-section is shown mounted upon the usual pivot rod 10, the structure or building to which the inner end of said pivot bar is secured, not being shown. Arranged beyond the pivot rod 10 is the counter weight 11 which is connected with the stair-section by means of the channel bar 12, the latter being rigidly secured to the pivoted end of the outervstringer. Also arranged upon the outer Stringer is the usual guard rail 13.

rlhe lower ends of the Stringer bars 3 and 1 are connected by means of a plate 14, the latter being secured to said bars by means of bolts 15 and nuts 16 threaded upon said bolts. Thel opposite ends of the Stringer bars 3 and 4 are connected by means of a plate 17, the respective edges of said plate being secured to said bars 4 and 5 by means of bolts 18 and 18 and nuts 19 and 19 threaded respectively upon said bolts.

1n constructing the stair-section the same is completed to every detail as above set forth with the exception of the insertion of the bolts 18 and the nuts 19 which are omitted. The structure in this condition is shown in Fig. 1 where it will be noted th at the lower end of the inner Stringer or the corner of the stair-section opposite to that bearing the counter weight sags. Before said bolts 18 and nuts 19 are applied, the Stringer bar 3 through the medium of the lever 20 is forced bodily toward said plate 17, this being done by engaging the lower bifurcated end of said lever with a stud 21 projecting from the bar 4 and forcing the intermediate portion of said lever against the stud 22 projecting from the bar 8 by engaging the upper or free end of said lever. By thus forcing the stringer bar 3 it will be observed that the lower end of the stiinger bar 4 will be forced upwardly, the entire structure being in fact strained in such a manner as to elevate the sagging corner of the stair-section bringing the same into the same horizontal plane with the corresponding corner thereof as shown in Fig. 2. When said stringer bar 3 is so moved, the bolt holes therein will be brought into alinement with the bolt holes provided in the plate 17 whereupon the bolts 18 will be inserted into position and the nuts 19 threaded thereon in order to maintain the structure in the abovementioned strained condition and hence the normally sagging corner thereof in proper position. Instead of the bolt holes being drilled in the bar 3 before straining the same as above described, it is evident that if desired, the same may be drilled after said bar has been moved to proper position and after drilling the bolts 18 inserted therein.

Vith the construction as set forth the sagging in the pivoted stair-section of a re escape which has been referred to may be avoided and with the expenditure of a minimum of time, labor and expense. A structure of the construction as set forth is durable and economical and the same is adapted to efficiently serve in the capacity for which -the same is designed.

Vhile I have illustrated and described the preferred form for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. I therefore do not wish to be limited to the precise details of construction as set forth, but desire to avail myself of such variations and modifications as come wit-hin the scope of the appended claims.

I-Iaving described my invention what I claim as new and desire to secure by Letters Patent is:

l. A fire escape comprising a pivoted stairsection, said section comprising stringers and steps extending between and connecting said stringers; a counter weight at one end of one of said stringers; and means for maintain- "ing a condition of strain resulting from a force applied to the upper edge of the other of said stringers longitudinally thereof and reacting against the lower edge thereof in the opposite direction, substantially as described.

2. A fire escape comprising a pivoted stairsection, said section comprising stringers and steps extending between and connecting said stringers; a counter weight at one end of one of said stringers, the other of said stiingers comprising two substantially parallel longitudinal bars; and means for maintaining a condition of strain resulting fioin a force applied to the upper bar of said last-inentioned stringer longitudinally thereof and reacting against the lower bar of said stringer in the opposite direction, substantially as described.

3. A fire escape comprising a pivoted stairsection, said section comprising stringers and steps extending between and connecting said stringers; a counter weight at one end of one of said stringers, the other of said stringers comprising two substantially parallel longitudinal bars; and plates connecting said bars for maintaining a condition of strain resulting from a force applied to the upper bar of said last-mentioned stringer longitudinally thereof and reacting against the lower bar of said stringer in the opposite direction, substantially as described.

4. A fire escape comprising a pivoted stairsection, said section comprising stringers and steps extending between and connecting said stringers; a counter weight at one end of one of said stringers, the other of said stringers comprising two substantially parallel longitudinal bars; and plates connecting said bars at the respective extremities thereof for maintaining a condition of strain resulting from a force applied to the upper bar of said last-mentioned stringer longitudinally thereof and reacting against the lower bar of said stringer in the opposite direction, substantially as described.

5. A fire escape comprising a pivoted stairsection, said stair-section comprising stringers and steps extending between and rigidly connecting said stringers, each of said steps comprising end pieces and treadforming bars extending between and rigidly secured in said end pieces, the other of said stringers comprising two substantially parallel longitudinal bars; and plates connecting said bars for maintaining a condition of strain resulting from a force applied to the upper bar of said last-mentioned stringer longitudinally thereof and reacting against the lower bar of said stringer in the opposite direction, substantially as described.

6. The method of constructing the pivoted stair-section of a fire escape which consists in providing two stringers; in providing a counter weight at one end of one of said stringers; in providing steps extending bctween and connecting said stringers; in forming the other of said stringers of two parallel separated longitudinal bars; in rigidly connecting corresponding ends of the latter; in securing a connecting plate to the opposite end of one of said bars; in forcing the free end of the other of said bars toward i name to this specification in the presence of said plate so as to strain said bars; and in two subscribing Witnesses.

rividly securing said free end of said free batir With said last-mentioned plate to main- CHARLES V' LINDHOLM tain said hars in strained condition, substan- Witnesses: tially as described. JOSHUA R. H. POTTS,

In testimony whereof I have signed my HELEN F. LILLIS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

